spike the lens
v. phr.— «In the final moments of the Munchkin Land scene, in which Glinda the good witch (played by Billie Burke) instructs Dorothy to follow the yellow brick road, it’s easy to spot young Priscilla, near Burke, as the youngster briefly peers directly into the camera, “spiking the lens” as it is called.» —“Trouble in ‘Oz’: the Munchkins’ dirty secret” by Stephen Cox Los Angeles Times Dec. 2, 2008. (source: Double-Tongued Dictionary)